Michyrus thomasi Skelley and Gasca-Álvarez, 2020

Skelley, Paul E. & Gasca-Álvarez, Héctor Jaime, 2020, Michyrus, a new genus of pleasing fungus beetles with coarsely faceted eyes (Coleoptera: Erotylidae), Insecta Mundi 2020 (836), pp. 1-8 : 3-5

Michyrus thomasi Skelley and Gasca-Álvarez , new species

Figures 1–9 .

Diagnosis. A member of the genus Michyrus , notably differs the other species of the genus ( M. yvineci ) in many characters including the pronotal disc finely, sparsely punctate; elytral striae punctures coarse and strongly impressed; prosternal hypomeron lacking coarse punctures; procoxal lines widely separated anteriorly, connecting across middle; mesoventrite with transverse groove connecting coxal lines anteriorly, and abdominal ventrite I lacking coxal line.

Description. Length: 6.9–8.3 mm; Width: 3.5–4.4 mm. Body elongate-elliptical, widest at elytral third ( Fig. 1 ), convex in lateral view ( Fig. 3 ) lacking microreticulations, strongly glossy, dorsally finely, sparsely punctate; body dark brown, with disc of pronotum laterally tan, elytra with vague tan marking at humerus and broad tan areas on apex, and all appendages tan.

Head width between eyes = 3 eye widths ( Fig. 4 ); ocular striae reach base of antennae; vertex puncture size = facet, separated by 3–4× diameters; epistome puncture size = facets, separated by 1× diameter. Antennae reach middle of pronotum; antennomere III as long as next 2 antennomeres combined; antennomeres IX–XI symmetrical; antennomere XI transversely oval ( Fig. 7 ).

Maxilla with terminal palpomere securiform, length = 0.5× width. Labium with terminal palpomere elongate, sides arcuate to narrow rounded apex. Terminal palpomere of labium width = 0.25 maxilla terminal palpomere width. Mentum with plate pentagonal ( Fig. 6 ), depressed below strong carina forming plate, length = width, all sides nearly equal in length, sides straight and parallel at base; ridge medial extension depressed in middle, carinate laterally to apex.

Pronotum with disc finely, sparsely punctate, punctures becoming coarser laterally, but are absent near lateral margins ( Fig. 5 ); sublateral coarse puncture size = an ocular facet, separated by 1–2 diameters. Scutellar shield pentagonal, length = 0.5× width. Elytra with strial punctures coarse and strongly impressed, puncture size on disc = 2× ocular facet diameter; intervals with fine to minute punctures.

Prosternum weakly keeled and strongly pinched anteriorly, rugose medially, smooth and impunctate laterally in front of coxa ( Fig. 2 , 6 ); prosternal plate with pores on each side near mid-length of procoxae; procoxal lines weakly sinuate, slightly concave at middle, length = 0.6× sternal length, lines converging anteriorly, anterior separation = 0.5× basal width of sternal process, curved inward anteriorly and weakly connecting across middle, barely surpassing coxae, length = basal width; prosternal plate apical width = half basal width; base shallowly concave; prosternal hypomeron with few poorly defined coarse punctures.

Mesoventrite with rugose transverse groove across disc connecting coxal lines anteriorly. Metaventrite with coxal lines meeting at middle, recurved; lines extend 0.33× distance to posterior lateral angle; entire surface of metaventrite with scattered minute punctures.

Abdominal ventrite I lacking coxal line ( Fig. 8 ); all ventrites coarsely punctate along anterior margin, becoming finely punctate near posterior margin. Female genitalia with spermathecal head kidney-shaped, tail narrow, tightly curved ( Fig. 9 ). Male unknown.

Material examined. Holotype female of Michyrus thomasi label data: “/ Barro Colorado I. / CZ Panama IX / 22,24,26 1986 / Henk Wolda // Trap 3b/” ( UCDC) . Paratypes (2 females): “/ Barro Colorado I. / CZ Panama VII- 21 / 23,25 1986 / Henk Wolda // Trap 2b/” (1 UCDC) ; “/ Barro Colorado I. / CZ Panama VII-21 / 23,25 1986 / Henk Wolda // Trap 4b/” (1 FSCA) .

Etymology. This species is named after Mike Thomas, who encouraged PES to study the Erotylidae .

Figures

Figures 1–5. Michyrus thomasi Skelley and Gasca-Álvarez, holotype female.1) Dorsal habitus. 2) Ventral habitus. 3) Lateral habitus. 4) Head and pronotum, anterior view. 5) Head and pronotum, dorsal oblique view. Photographs by PES.

Figures 6–10. Miscellaneous structures. 6–8) Michyrus thomasi Skelley and Gasca-Álvarez, holotype female. 6) Head and prothorax, ventral view. 7) Antenna, ventral view. 8) Abdomen, ventral view. 9–10) Female genitalia. 9) Michyrus thomasi Skelley and Gasca-Álvarez, paratype. 10) Michyrus yvineci Skelley and Gasca-Álvarez, holotype. Photographs 6–9 by PES, 10 courtesy Jean-hervé Yvinec.